Abstract: Systems, methods and instrumentalities are disclosed for WTRU-initiated beam recovery including beam switching and/or beam sweeping. A WTRU may be configured to detect a beam failure condition, identify a candidate beam for resolving the beam failure condition, and send a beam failure recovery request to a network entity. The WTRU may include the candidate beam in the beam failure recovery request and may receive a response from the network entity regarding the request and/or a solution for the beam failure condition. WTRU-initiated beam recovery may be used to resolve radio link failures and improve system performance by avoiding the necessity to perform an acquisition procedure. Additionally, beam sweeping may be performed at a sub-time unit level to provide a fast sweeping mechanism.

Abstract: Embodiments described herein provide systems and methods for reference signal configuration for multiple panels with panel-specific channel state information reference signals (CSI-RS) configurations and quasi-collocation (QCL) indication, including QCK type definition and indication for panel-specific CSI-RS configurations. Exemplary embodiments further provide multi-component precoder structure with panel specific component precoder and panel common precoder. Embodiments include: (semi)-open-loop schemes using random precoding for panel common precoder and/or panel specific precoder; panel selection/restriction with panel common precoder; MU-MIMO operation using different set of panels; and panel-wise CSI reporting.

Abstract: A method and wireless transmit/receive unit (WTRU) include a WTRU configured to search a frequency bandwidth, out of a set of potential frequency bandwidths, for synchronization signals. The frequency bandwidth includes a secondary synchronization signal in subcarriers. Other subcarriers in the frequency bandwidth outside of the secondary synchronization signal include data. The WTRU is configured to synchronize using the secondary synchronization signal in the frequency bandwidth.

Abstract: Latency reduction by fast forward (FF) in multi-hop communication device and/or systems is disclosed. Packets may be received and forwarded using a codeword (CW)-based approach with and/or without per-CW CRC. A FF session may have a flow ID and packets may have sequence numbers. Packets targeted for FF may be divided into independently decodable CWs that may be transmitted in the next hop, for example, as soon as the destination is determined without waiting for an entire packet's arrival and/or for CRC verification. Low latency (e.g. FF) traffic may be indicated. CW-based FF may be extensible for an e2e RAN path from a WTRU to the last access node in a RAN. Intermediate metrics, a packet CRC and/or a per-CW CRC may be utilized for data integrity. HARQ and/or CW retransmission procedures may be implemented between network nodes for error handling.

Abstract: A method and apparatus for performing sidelink communications in a wireless transmit receive unit (WTRU) using Long Term Evolution (LTE) and New Radio (NR) technologies is described herein. A WTRU receives downlink control information (DCI) on a physical downlink control channel (PDCCH) from a gNodeB (gNB), wherein the DCI is associated with a cyclic redundancy check (CRC). The a determination is made as to whether the DCI is for an LTE or NR technology sidelink transmission. On a condition that the DCI is for NR technology, the WTRU determines which transmit modulation and coding scheme (MCS) table to apply based on the masking of at least some of the bits in the CRC. Then the WTRU transmits sidelink data on resources indicated by the DCI using the determined MCS table. The WTRU may also receive HARQ feedback on resources indicated by the DCI for HARQ feedback.

Abstract: In an integrated access and backhaul (IAB) system, an access WTRU may receive a random access channel (RACH) occasion (RO) configuration comprising one or more RO resources from a first integrated access backhaul (IAB) node. The access WTRU may receive an indication that one or more of the configured RO resources have an overlap with one or more IAB node RO resources. The access WTRU may monitor and receive the ROI indicating the configured RO resources that overlap with the one or more IAB node RO resources. Based on the received ROI and the configured RO resources, the access WTRU may determine one or more RO resources available for PRACH transmission. The access WTRU may select an RO resource from the available RO resources for PRACH transmission. The access WTRU may send a first PRACH transmission to the first IAB node using the selected RO resource.

Abstract: Systems, methods, and instrumentalities are disclosed for error check-based synchronization. Physical Broadcast Channel (PBCH) data may be determined. A scrambling (e.g., a first scrambling) of the PBCH data may be scrambled via a sequence (e.g., a first sequence). The first sequence may be based on a cell ID and/or timing information. Error check bits may be attached to the scrambled PBCH data and to the timing information. The error check bits may include one or more cyclic redundancy check (CRC) bits. The scrambled PBCH data, the timing information (e.g., the unscrambled timing information), and/or the attached error check bits may be polar encoded. The polar encoding may result in polar encoded bits. A scrambling (e.g., a second scrambling) of the polar encoded bits may be scrambled via a sequence (e.g., a second sequence). The first sequence and the second sequence may be different. The polar encoded bits may be transmitted.

Abstract: Systems, methods and instrumentalities are disclosed for WTRU-initiated beam recovery including beam switching and/or beam sweeping. A WTRU may be configured to detect a beam failure condition, identify a candidate beam for resolving the beam failure condition, and send a beam failure recovery request to a network entity. The WTRU may include the candidate beam in the beam failure recovery request and may receive a response from the network entity regarding the request and/or a solution for the beam failure condition. WTRU-initiated beam recovery may be used to resolve radio link failures and improve system performance by avoiding the necessity to perform an acquisition procedure. Additionally, beam sweeping may be performed at a sub-time unit level to provide a fast sweeping mechanism.

Abstract: Random access may be provided for integrated access and backhaul (IAB) for New Radio (NR). A wireless transmit/receive unit may send (e.g., to a gNB) a preamble in a random access occasion (RO). One or more of the preamble or an RO resource partition of the RO may indicate a node type of the WTRU. The WTRU may receive (e.g., from the gNB) a physical downlink control channel (PDCCH) that indicates (e.g., includes) one or more random access responses (RARs). The WTRU may determine that the PDCCH indicates a WTRU RAR and an integrated access and backhaul (IAB) node RAR. If the sent node type is a WTRU node type, the WTRU may receive (e.g., from the gNB) the WTRU RAR at a first time and frequency location indicated by the PDCCH.

Abstract: Systems, methods, and instrumentalities are disclosed for interleaving coded bits. A wireless transmit/receive unit (WTRU) may generate a plurality of polar encoded bits using polar encoding. The WTRU may divide the plurality of polar encoded bits into sub-blocks of equal size in a sequential manner. The WTRU may apply sub-block wise interleaving to the sub-blocks using an interleaver pattern. The sub-blocks associated with a subset of the sub-blocks may be interleaved, and sub-blocks associated with another subset of the sub-blocks may not be interleaved. The sub-block wise interleaving may include applying interleaving across the sub-blocks without interleaving bits associated with each of the sub-blocks. The WTRU may concatenate bits from each of the interleaved sub-blocks to generate interleaved bits, and store the interleaved bits associated with the interleaved sub-blocks in a circular buffer. The WTRU may select a plurality of bits for transmission from the interleaved bits.

Abstract: Systems, methods, and instrumentalities may be provided for an infrastructure node to transmit and a wireless transmit/receive unit (WTRU) or a group of WTRUs to receive a first downlink control information (DCI) a second DCI. The first DCI may carry time critical DCI, whereas the second DCI may carry non-time critical DCI. Each of the first DCI and the second DCI may be polar encoded. The second DCI may be polar encoded may be received with an embedded first DCI as part of frozen bits. The second DCI may be mapped to a plurality of bit channels having higher reliability than the plurality of bit channels to which the embedded first DCI is mapped. The WTRU may discard the decoded first DCI, if decoding of the DCI using the embedded first DCI is not successful.

Abstract: A method of feedback in a wireless transmit receive unit includes providing a precoding matrix index (PMI), error checking the (PMI) to produce an error check (EC) bit, coding the PMI and the EC bit and transmitting the coded PMI and EC bit.

Abstract: Methods and an apparatus for performing synchronization in New Radio (NR) systems are disclosed. A frequency band may be determined and may correspond to a WTRU. On a condition that the operational frequency band is a lower frequency, a synchronization signal block (SSB) index may be implicitly. On a condition that the operational frequency band is a higher frequency, an SSB index may be determined based on a hybrid method which includes determining the SSB index using both an implicit and an explicit method. A configuration of actually transmitted SSBs may be determined using a multi-level two stage compressed indication where SSB groups are determined based on a coarse indicator and actually transmitted SSBs with the SSB groups are determined based on a fine indicator.

Abstract: A method includes receiving a time domain resource allocation (TDRA) list configuration including entries, each including a resource allocation that includes a slot offset value. L1 signaling is received indicating a minimum slot offset value. Downlink control information (DCI) is decoded on a physical downlink control channel in a slot. An index is obtained from the decoded DCI, identifying an entry in the TDRA list. A particular slot offset value identified by the index is retrieved from the TDRA list and compared with the minimum slot offset value. If the particular slot offset value is less than the minimum slot offset value, the entry is invalid. If the particular slot offset value is greater than or equal to the minimum slot offset value, a physical downlink shared channel is received.

Abstract: Methods and apparatus for beam management are disclosed. A WTRU may include a plurality of antenna panels, each antenna panel comprising a plurality of antennas configured to transmit on directional transmit (TX) beams. The WTRU may send, to a transmission reception point (TRP), antenna panel capability information for the plurality of antenna panels and receive a reference signal (RS) configuration for configuring RS resource sets. The WTRU may send an RS transmission trigger frame identifying triggered RS resource sets from the configured RS resource sets. The WTRU may identify a set of antenna panels to be used with the triggered RS resource sets. The WTRU may determine an UL TX beam sweeping mode and an association between the triggered RS resources sets and the set of antenna panels. The WTRU may perform UL beam sweeping using the triggered RS resource sets and associated set of antenna panels.

Abstract: A method and apparatus for synchronization in an orthogonal frequency division multiplexing (OFDM) network is disclosed. A wireless transmit/receive unit (WTRU) is configured to receive a primary synchronization signal and a secondary synchronization signal from a cell. The primary synchronization signal and the secondary synchronization signal are spaced by a known number of OFDM symbols. The primary synchronization signal and the secondary synchronization signal are received in a same number of subcarriers in their respective OFDM symbol. A location of at least the secondary synchronization signal in the system bandwidth is variable.

Abstract: A wireless transmit/receive unit (WTRU) may receive sounding reference signal (SRS) resource configuration information. The WTRU may also receive beam indication (ID) information and panel ID information in downlink control information (DCI) and determine a WTRU panel based on the panel ID information or the SRS resource configuration information. The WTRU may also determine uplink (UL) beam sweeping for each determined WTRU panel based on the beam ID using one or more sweeping parameters.

Abstract: A WTRU may include a memory and a processor. The processor may be configured to receive beam grouping information from a gNB or transmission and reception point (TRP). The beam grouping information may indicate a group of beams that the WTRU may report using group-based reporting. The group-based reporting may be a reduced level of reporting compared to a beam-based reporting. The group-based report may include measurement information for a representative beam. The representative beam may be one of the beams in the group or represents an average of the beams in the group. Alternatively, the representative beam may be a beam that has a maximum measurement value compared to other beams in the group. The group-based report may include a reference signal received power (RSRP) for the representative beam and a differential RSRP for each additional beamin the beam group.

Abstract: A method and apparatus for performing autonomous transmission for performing collision mitigation and complexity reduction for non-orthogonal multiple access (NOMA) transmissions are disclosed. A wireless transmit/receive unit (WTRU) may receive a configuration with multiple SRs and associated preamble subsets, randomly select a preamble subset and select a SR configuration according to the randomly selected preamble subset based on the received configuration. The WTRU may transmit an SR associated with the selected preamble subset. Next the WTRU may select a preamble from the selected preamble subset, and transmit the selected preamble with a data transmission. Each SR associated with preamble subsets may be distinguished by time and frequency resources, sequence index value, or PUCCH index value.

Abstract: Systems, methods, and instrumentalities are disclosed for error check-based synchronization. Physical Broadcast Channel (PBCH) data may be determined. A scrambling (e.g., a first scrambling) of the PBCH data may be scrambled via a sequence (e.g., a first sequence). The first sequence may be based on a cell ID and/or timing information. Error check bits may be attached to the scrambled PBCH data and to the timing information. The error check bits may include one or more cyclic redundancy check (CRC) bits. The scrambled PBCH data, the timing information (e.g., the unscrambled timing information), and/or the attached error check bits may be polar encoded. The polar encoding may result in polar encoded bits. A scrambling (e.g., a second scrambling) of the polar encoded bits may be scrambled via a sequence (e.g., a second sequence). The first sequence and the second sequence may be different. The polar encoded bits may be transmitted.